Field of the Invention
The present invention relates to a projection lens and a projection display apparatus, and more particularly to a projection lens suitable for magnifying and projecting an original image formed, for example, by a light valve, and a projection display apparatus using the same.
Description of the Related Art
Heretofore, projection display devices (projectors) that magnify and project images displayed on image display surfaces of light valves, such as a liquid crystal display device, a DMD (Digital Micro-mirror Device: registered trade mark), and the like, have been used when conducting presentations and the like. When an image is projected, it is preferable that the contour of the magnified projected image on the screen is not distorted and there is no color shift in a peripheral portion of the magnified projected image. To that end, the projection lens is required to have a high resolving power with well-corrected distortion and lateral chromatic aberration. Further, from the viewpoint of downsizing, light-weighting, and cost reduction, the number of lenses of a projection lens needs to be as small as possible on the condition that the projection lens satisfies required specifications and performance. Further, there has recently been an increasing demand for wide angle lenses because large screen sizes with short projection distances are often required. To meet these needs, projection lenses that use an aspherical lens having a high aberration correction effect are proposed as described, for example, in Japanese Unexamined Patent Publication No. 2002-072094, Japanese Patent No. 3487468, Japanese Unexamined Patent Publication No. 2005-084352, and Japanese Patent No. 4060075.